Ejection mechanism for scraper



J. N. JOHNSON ET AL 3,479,758

-ECTION [v'IECHANISM FOR SCRAFE'R Nov. 25, 1969 3 Sheets-Sheet 1 Filed Aug. 28, 196? MW w W, m b M A, x, mw% www M Ta Nov. 25, 1969 .1. N, JOHNSON ET AL 3,479,758

EJECTION MECHANISM FOR SCRAPER Filed Aug. 28, 196'? 3 Sheets-Sheet 2 Gl m/ ,5 JA /2p 3 44mm pmmg L k/2m Fm W M @WPM 3 Sheets-Sheet .3

Nov. 25, 1969 JOHNSON ET AL EJECTION MECHANISM FOR SCRAPER Filed Aug. 28, 1967 nited States Patent US. Cl. 37-129 Claims ABSTRACT OF THE DISCLOSURE An ejection mechanism for aself-loading scraper in which a single hydraulic ram is operable to move a pushout type ejector and a bottom door to achieve complete ejection of material from the interior of the bowl. One of the two expansible and contractible components of the hydraulic ram is connected directly to the rear of the ejector and the other component of the ram is connected to an upright lever which has its upper end connected to the scraper frame and its lower end connected through a link to the bottom door. Thus, when the hydraulic ram is completely expanded the ejector will have been moved forwardly in the bowl to its eject position and the bottom door will have been moved rearwardly to its full open position exposing an opening in the bottom of the scraper bowl. Suitable stop means are provided to insure proper functioning of the ejector and bottom door operating mechanism.

This invention relates to a motor scraper ejection means wherein a single ram is employed to operate a push-out type ejector and a reciprocable bottom door section of the bowl bottom.

Heretofore others have employed a pair of rams to separately perform the functions of operating the push-out type ejector and bottom door of scraper bowls. This type of ejection system has been used particularly in elevating type scrapers, that is, scrapers using an endless conveyer type mechanism to move the material from the cutting edge rearwardly into the bowl.

Heretofore it has also been proposed to employ a single hydraulic ram to operate the rear wall or push-out type ejector and bottom door through a pair of levers. However, this prior mechanism is not entirely satisfactory due to its employment of an excessive number of parts to achieve the desired functions.

It is a primary object of the present invention to provide a mechanism for operating an ejector and a bottom door of an earthmover utilizing a single ram and a minimum of linkage mechanism.

It is a further object of this invention to provide an ejector and bottom door operating mechanism of the hereinbefore outlined character which is low in cost and gives satisfactory performance with a minimum of servicmg.

These and other objects of this invention will be apparent to those familiar with the art when the following description is read in conjunction with the drawings in which:

FIG. 1 is a side view of a self-loading motor scraper with parts broken away to show incorporation of the present invention;

FIG. 2 is a top view of the scraper shown in FIG. 1;

FIG. 3 is a top view of the bottom door operating link;

FIG. 4 is a section view of the ejector and bottom door operating apparatus of this invention with the bottom door shown in its retracted position and the ejector shown in its rear most position;

FIG. 5 is a view similar to FIG. 4 except showing the ejector moved forwardly to its eject position; and

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FIG. 6 is a section view taken along the line VI-VI in FIG. 1.

Referring to FIGS. 1 and 2, the present invention is shown incorporated in a self-propelled earthmover which includes a two wheeled tractor unit 11 and a two wheeled scraper unit 12 interconnected for articulative steering about a vertical pivot axis 13 through the pivotal connection of a draft yoke 14 to a vertical king pin 16. The king pin 16 is a part of an intermediate hitch member 17 which is pivotally connected to the frame of the two wheeled tractor for pivotal movement about a longitudinal axis 18. As shown in FIG. 2, the draft frame 14 has a pair of rearwardly extending legs 21, 22 which are pivotally connected to the vertical side walls 23, 24 on a transverse pivot axis 26.

The vertical side walls 23, 24 of the scraper bowl 25 are interconnected by a bottom wall 31, a cutting edge structure 32 and a rear frame 33. A pair of rear support wheels 34, 36 are mounted on the frame 33 in a conventional manner. An endless conveyer or elevating mechanism 37 is provided at the forward end of the scraper bowl to move excavated material from the cutting edge 32 rearwardly into the bowl 25. The endless conveyer mechanism is driven by suitable power means 38. The frame of the elevating mechanism includes a pair of rearwardly extending arms 39, 41 which are pivotally connected at their rear ends to the side walls 23, 24 of the scraper bowl. Downward swinging movement of the elevator mechanism is limited by engagement of transverse brace member 42 with pads 43, 44 on the side walls 23, 24 and upward swinging movement of the elevator mechanism is limited by engagement of the transverse member 42 with stops 46, 47 on the draft arms 21, 22, respectively.

The bowl 25 presents a bottom opening between the stationary bottom wall 31 and the blade structure 32. During loading and transport operations this bottom opening is closed by a longitudinally shiftable bottom door 51. The bottom door 51 is mounted for longitudinal, reciprocable movement between a forward, closed position as illustrated in FIG. 1, wherein it forms an extension of bottom wall 31, to a rearward, open position, in which the bottom door is disposed below the bottom wall 31 and excavated material is permitted to fall through the bottom opening. The open position of door 51 is illustrated in FIGS. 4 and 5. The bottom wall 51 is supported on the side walls through four rollers 52 at each side which are pivotally mounted on brackets 53, 53. The rollers '52 are disposed for guided rolling engagement in channels 54, 55 welded to the outer sides of side walls 23, 24. A strike-off edge structure 61 is pivotally connected to the forward end of the bottom door 51 for pivotal movement about a transverse pivot axis 62. In the forward position of the bottom door as illustrated in FIG. 1, upstanding fingers 63, 63' on the strike-off edge structure 61 engage abutments 64, 64' rigidly secured to the side walls 23, 24, thereby forcing the strike-01f edge 61 to swing upwardly to its position illustrated in FIG. 1, wherein it abuts the cutting edge brace member 60. When the bottom door is retracted the strike-off edge swings down to the position illustrated in FIGS. 4 and 5, wherein it is disposed for proper leveling of material being ejected from the scraper.

The push-out type ejector 66 includes a transverse wall 71 which forms a rear wall of the scraper bowl when in its retracted position illustrated in FIG. 1. The ejector is guided for movement within the bowl between its retracted position shown in FIG. 1 and its eject position shown in FIG. 5, by a pair of guide elements in the form of rollers 67, 68 pivotally mounted on the rear end of a guide structure 69 rigidly secured to the transverse wall 71 of the ejector and extending rearwardly therefrom. The rollers 67, 68 are A guide mechanism in the forni ofclfafinel parts 72, 73 rigidly secured as by welding to frame 33.

The ejector 66 and bottom door 51 are operated by a novel actuating mechanism including a longitudinally disposed double acting hydraulic ram 76 and linkage 77 interconnecting the frame'33, ram 76 and bottom door 51. The ram 76 includes a pair of relatively extensible and contracti'ble elements in the form of a piston 78 and cylinder 79. The piston includes a rod part 81 'pivo 'tally connected at its forward end to a bracket 82 rigidly secured to the rear of wall 71 of'the ejector' 66. The cylinder 79 is universally connectedto a vertically jdisposed lever 83 which is pivotally connected at" its uppe'r"end on transverse axis 84 to'the scraper bowlliframe The lower end of the vertically disposedleve'r 83is'pivotally connected to a longitudinally disposed link 8 6 oria trans;

verse pivot axis 87. The forward end'of the longitudinal the ejector in its longitudinal reciprocation within the link 86, shown in plan view in FIG. 3, ispivotally connected on a transverse 'ax is 88 to bo' ttom :door 51 by pins 89, 90. As shown in FIG. 6' t he cylinder 79 is universally connected to thelaterallyfspaced legs 91', 92 of lever 83 through a gimbal93 which ispivotally connected to the legs 91, 92 onaxis 94 and pivotally connected to the ram on axis 96. The legs 91, 92 of the lever 83 are disposed on opposite sides of the ram cylinder 79, intermediate the cylinder 79 and the guide elements 67, 68.

OPERATION When it is desired to excavate with the earthmover, the scraper bowl 25 is lowered by expanding the double acting cylinders 101, only one of which is shown, which interconnect the draft frame 14 and the scraper bowl 25. This lowers the bowl 25 into the ground to be excavated and during forward motion of the earthmover the bowl is filled with excavated material. 'Upon the bowl being filled, the hydraulic jacks 101 are contracted to raise the bowl to the transport position as illustrated in FIG. 1, and the earthmover is driven to the location where the material is to be unloaded. Usually it is desired to spread the material evenly, hence the provision of the strike-01f structure 61.

When it is desired to commence dumping and spreading the material, the ram 76 is expanded to sequentially retract the bottom door 51 and push the ejector 66 forwardly. The ram 76 and linkage are connected and arranged in such a manner that the resistance to movement of the bottom door is overcome prior to overcoming the resistance to movement of the ejector 66. Thus the bottom door 51 is retracted to its position beneath the bottom wall 31 as shown in FIG. 4 prior to forward movement of the ejector 66. When the ram has moved the lever 83 rearwardly to retract the bottom door 51 to its position shown in FIG. 4, the cross brace 102 on the bottom end of lever 83 abuts stops 103 rigidly mounted on the frame 33. Further expansion of the ram 76 moves the ejector forwardly to the position shown in follows:

FIG. 5. Forward motion of the ejector 66 ceases when the ram reaches the end of its stroke.

After unloading the scraper, the ejector 66 and bottom door 51 are returned to their loading position, as shown in FIG. 1, by contracting ram 76. If the bottom door moves first to its closed position, the strike-off edge structure 61 will abut against the stops formed by abutments 64, 64' and cutting edge brace member 60. When this occurs, further contraction of theram forces the ejector 66 to the rear until the piston 78 bottoms out at the closed end of the cylinder 79. If, duringcontraction of ram 76, the ejector moves rearwardly before the bot- .tom door moves forwardly, it will-move to the rear until the ejector guide rollers 67, 68 abut stops 106, 106 on channel parts 72, 73 and then further contraction of ram 76 will move the bottom door forwardly. 2

Stops .107, 107 on channel parts 72, 73 serve to limit forward movement of ejector 66 in case it should move through its forward ejection stroke before the bottom door 51 moves rea rwardly. Such a sequence of movement is not normal but could occur if, for instance, the bottom door jams for any reason.

' From the foregoing description it is apparent that an extremely convenient and effective operating means is provided 'for the ejector and bottom door of a scraper bowl. The design provides efficient application of force by the ram 76 to the ejector and bottom door components. By connecting the ram 76 directly to the ejector, in accordance with the present invention rather than through a motion multiplying lever, a smaller diameter ram may be employed to eject'a predetermined load. The single longitudinally disposed ram 76 is placed in the vertical central longitudinal plane 108 of the scraper to provideefiicien't, effective application of force to the ejector and bottom door. The laterally spaced guide chan he ls 72 173 on frame 33 serve to stabilize as well as guide li] Theembodiments of the invention in which an exclusive property or privilege is claimed are defined as 1. In a scraper bowl having side walls rigidly interconnected by a bottom wall and a frame extending rearwardly of said side walls, the combination comprising:

an injector shiftable longitudinally within said bowl including a transverse wall forming the rear wall of said bowl and a guide structure rigidly secured to and extending rearwardly from said transverse wall,

guide means on said frame rearwardly of said side walls structure for longitudinally guiding the latter,

a bottom door mounted on said bowl for longitudinal reciprocable movement between a closed position in which it is disposed forwardly of and in extending relation to said bottom wall and anopen position in which it is disposed beneath said bottom wall,

a longitudinally disposed double acting hydraulic ram having a'pair of relatively extensible and contractible elements,

first pivot means connecting one of said elements directly to said ejector, and

a linkage interconnecting the other of said elements,

frame and bottom door including a vertically disposed lever,

second universal pivot means pivotally connecting said lever intermediate its vertical length directly to said other element, and

means pivotally connecting the upper and lower ends of said lever to said frame and bottom door, respectively.

2. The combination set forth in claim 1 wherein said ram is disposed approximately in the vertical central longitudinal plane of said how], said guide structure includes a pair of guide elements at its rear end disposed on laterally opposite sides of said ram and said mechanism includes laterally spaced parts in cooperative guiding engagement with said guide elements.

3. The combination of claim 1 wherein said one element is a piston having a rod part, said other element is a cylinder, said first pivot means pivotally connects said rod part to the rear of said ejector and said second pivot means pivotally connects aid cylinder to a vertically intermediate part of said lever for universal movement relative thereto.

4-. The combination of claim 3 wherein said lever includes laterally spaced and vertically disposed legs on opposite sides of said cylinder and wherein said second pivot means includes a gimbal.

'5. Thhe combination of claim 3 wherein said ram is disposed approximately in the vertical central plane of said bowl, said guide structure includes a pair of guide elements at its rear end disposed on laterally opposite sides 5 of said ram and said mechanism includes laterally spaced 3,274,711 parts in cooperative guiding engagement with said guide 3,300,882 elements. 3,303,587 References Cited 3,325,925

UNITED STATES PATENTS 2,994,976 8/1961 Hancock 37129 XR 3,057,090 9/1962 Mazzarins 37-126 3,066,429 12/1962 Hancock 37--129 37-126 Johnson et a1. 37-1'29 Fryer 37-129 Rockwell 37-129 XR Hermiz et a] 37--124 5 EDGAR s. BURR, Primary Examiner us. 01. X.R.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3, 479,758 Dated November- 25, 1969 Inv n fl James NJ Johnson and Donald Di Lorene It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

' Column 4, line 27, "injector" should read ejector --3 line 33, after the word "walls" insert includin mechanism cooperating with said guide and line 72, "'I'hhe should read $|GNED AND SEALED MAR 101970 (SEAL) Aneet:

EdwardMFletcher,Jz-.

WILLIAM E. SGH'UYL'ER, JR.

Attesting Officer Oomissioner of Patents 

